Ethanol production from sugarcane straw using different configurations of fermentation and techno-economical evaluation of the best schemes

This work analyzed different processes of ethanol fermentation from pretreated sugarcane straw. The conversion process, addressing enzymatic hydrolysis and fermentation of C5 and C6-sugars, and the determination of two economic indicators of the best configuration, were covered in this study. Design of experiments combined with Desirability function were applied to select the best combination of glucose concentration and yield in the enzymatic hydrolysis step, resulting in a glucose yield similar to 30g/100 g of initial raw material under conditions of 13% of solid load and 30 FPU/g pretreated SCS. In addition, some fermentation configurations were evaluated. A presaccharification previous to simultaneous saccharification and fermentation (PSF) had a higher result in ethanol concentration and yield. The application of this configuration and fermentation of C5 sugar from the pretreatment step yields 215.05 L/ton SCS. Return of investment and payback period, as economic indicators, suggest that the alternative PSF is suitable for adoption by sugarcane industry under the evaluated conditions. (C) 2020 Elsevier Ltd. All rights reserved.